Issues

• goto-instrument --apply-loop-contracts aborts (local_may_alias.cpp) on a GOTO binary previously processed by --unwindset

  diffblue/cbmc#9217 · Filter by author rcalvom opened on Oct 19, 2026

• SMT2 back end: overflow flag and value of a checked multiplication swapped in the flattened (no-datatype) encoding (--bitwuzla)

  diffblue/cbmc#9215 · Filter by author admercs opened on Oct 16, 2026

• fmod/fmodf return 0 for finite operands with a nonzero remainder (fmod(7, 2) gives 0)

  diffblue/cbmc#9214 · Filter by author JeroenRobben opened on Oct 16, 2026

• SAT and SMT2 backends disagree on extending integer-to-pointer and pointer-to-integer casts

  diffblue/cbmc#9212 · Filter by author JeroenRobben opened on Oct 15, 2026

• SMT2 backend: array equality also compares elements outside the array bounds (spurious failures)

  diffblue/cbmc#9211 · Filter by author JeroenRobben opened on Oct 15, 2026

• --fpa: signbit() of a negative NaN is always 0

  diffblue/cbmc#9209 · Filter by author JeroenRobben opened on Oct 15, 2026

• --fpa: bit pattern of a NaN float is unconstrained, so byte-level access to floats gives spurious counterexamples

  diffblue/cbmc#9208 · Filter by author JeroenRobben opened on Oct 15, 2026

• SMT2 backend: is_dynamic_object only knows objects seen so far and is false for all others

  diffblue/cbmc#9207 · Filter by author JeroenRobben opened on Oct 15, 2026

• SAT backend sign-extends enums whose underlying type is unsigned

  diffblue/cbmc#9206 · Filter by author JeroenRobben opened on Oct 15, 2026

• fp.rem / __CPROVER_remainder do not compute the IEEE 754 remainder (remainder(5, 3) gives +0)

  diffblue/cbmc#9204 · Filter by author JeroenRobben opened on Oct 15, 2026

• remainder/remainderf/remainderl library models pass swapped arguments to __CPROVER_round_to_integral*

  diffblue/cbmc#9203 · Filter by author JeroenRobben opened on Oct 15, 2026

• __builtin_{add,sub,mul}_overflow with operands of different types misses overflows

  diffblue/cbmc#9202 · Filter by author JeroenRobben opened on Oct 15, 2026

• SMT2 backend without FPA: double results that round up to a power of two become a subnormal (int shift overflow in float_bvt::round_fraction)

  diffblue/cbmc#9200 · Filter by author JeroenRobben opened on Oct 15, 2026

• --z3/--cvc5: map::at exception (exit status 6) while converting a goto program that contains Rust's core::fmt::Formatter

  diffblue/cbmc#9190 · Filter by author Talha-Dmr opened on Oct 14, 2026
  1

• Quantifier whose body is a statement expression: a short-circuit path that skips the final expression is dropped, so false __CPROVER_exists/__CPROVER_forall assertions verify

  diffblue/cbmc#9189 · Filter by author Talha-Dmr opened on Oct 14, 2026

• goto-cc doesn't record "static" and "const" qualifiers on formal array parameters?

  diffblue/cbmc#9183 · Filter by author rod-chapman opened on Oct 13, 2026
  6

• SMT2 backend truncates shift distance when it is wider than the shifted operand

  diffblue/cbmc#9177 · Filter by author kroening opened on Oct 7, 2026

• Incorrect value from __builtin_va_arg on a va_list element pointer passed to a function

  diffblue/cbmc#9176 · Filter by author 71iq opened on Oct 6, 2026

• DFCC loop contracts: a variable declared before a loop without an initializer is not havoced, so a false assertion verifies

  diffblue/cbmc#9175 · Filter by author Talha-Dmr opened on Oct 5, 2026

• Byte update with a symbolic size at a non-zero offset into a scalar overwrites bytes beyond the size (unsound)

  diffblue/cbmc#9173 · Filter by author bardiharborow opened on Sep 29, 2026

• Byte update with a symbolic size starting mid-element never writes the following element (unsound)

  diffblue/cbmc#9172 · Filter by author bardiharborow opened on Sep 29, 2026

• Byte update with a symbolic size does not write the partially covered last array element (unsound)

  diffblue/cbmc#9171 · Filter by author bardiharborow opened on Sep 29, 2026

• Byte update with a symbolic size skips the last element when the size is a multiple of the element size (unsound)

  diffblue/cbmc#9170 · Filter by author bardiharborow opened on Sep 29, 2026

• CBMC missing an error after exiting do-while loop

  diffblue/cbmc#9169 · Filter by author mksvoboda97 opened on Sep 24, 2026

• Integer.getInteger model recurses unconditionally

  diffblue/cbmc#9168 · Filter by author lemmy opened on Sep 24, 2026